Here you are some interesting web resources for children to use to create a digital image.
Many of them use Flash. So you will need to capture the image you want by taking a screen picture with the PrintScreen key, with Grab or Jing or whatever other program: as soon as you have the capture... just use your imagination!

Incredible@art Probably one of the best sites! 126 links to pages with art games,experiments, digital art...

PicassoHead. Children can drag face elements to the canvas and make a painting in a Picasso style.

Iconscrabble. It is in German. Children type a word up to 18 characters into the box (Begriffe eingeben). They click Scrabble to see their word converted into icons. Then press “Bild herunterladen” to generate a png image.

Graffiti Creator. Children can create a “professional-look" graffiti from any selected word. They play with the settings until they generate what they want.

Dreamlines: Type in a word or words and it generates dream-like images that change before your eyes.

Bomomo .Using the icons from the bottom of the screen, children click and drag on the screen and see the results. They repeat as many times as they want.